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Product Design Concept and Application
Concept Generation
Krates Ng
Fall 2008
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Five Steps e.g. A cordless electric roofing nailer
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Step 1) Clarify the problem Based on the assumptions
• Mission statement • The nailer inserts nails in rapid in succession
– To “design a better hand-held roofing nailer” • The nailer is lightweight
• Assumptions
• The nailer has no noticeable nailing delay after
– The nailer will use nails
tripping the tool
– The nailer will be compatible with nail magazines
on existing tools
– The nailer will nail through roofing shingles into
wood
– The nailer will be hand-held
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Decompose a complex problem into
Basic needs to target specs
simpler subproblems
• Nail lengths from 25mm to 38mm • Functional decomposition
• Max. nailing energy of 40j per nail First Step
A single black box
• Nailing forces of up to 2000N
• Peak nailing rate of one nail per second
• Average nailing rate of 12 nails per min.
• Tool mass less than 4Kg Second Step
Divide the single black
• Max. trigger delay of 0.25 secs. box into sub-functions
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Two other approaches
• Decomposition by sequence of user actions • Decomposition by key customer needs
– Useful for products with very simple technical – Useful for products in which form, and not
functions involving a lot of user interaction. working principles or technology, is the primary
– e.g. the nail problem might be broken down into 3 problem.
user actions: moving the tool to the gross nailing – E.g. for the nailer, this decomposition might
position, positioning the tool precisely, triggering include the following sub-problems: fire nails in
the tool. rapid succession, is lightweight, and has a large
nail capacity.
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Step 2) Search Externally
• Find existing solutions to both the overall – Search patents
problem and the sub-problems. • http://www.google.com/patents
– Search published literature
– Five good ways to gather information
• http://scholar.google.com
• Lead users: are those users of a product who
• Library, magazines…etc.
experience needs months or years before the majority
of the market and stand to benefit substantially from a – Benchmark related products
product innovation. • Study of existing products with functionality simialr to that
– e.g. nailer -> building contractors of the product under development or to the subproblems on
which the team is focused.
• Consult experts: professionals at firms manufacturing
related products, professional consultants, university • Can reveal existing concepts that have been implemented to
solve a particular problem, as well as information on the
faculty…etc. strengths and weaknesses of the competition.
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Step 3) Search Internally Individual and Group Sessions
• Suspend judgment • Both can be useful
• Generate a lot of ideas • e.g.
• welcome ideas that may seem infeasible – The nailer team used both. During one week each
member was assigned one or two subproblems
• Use graphical and physical media
and was expected to develop at least 10 solution
concepts. The group then met to discuss and
expand on the individually generated concepts.
The more promising concepts were investigated
further.
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Hints for generating solution concepts
• Make analogies • Use unrelated stimuli
– e.g. to choose at random one of a collection of
– What other devices solve a related problem. photographs of objects, and then to think of some
• Wish and wonder way that the randomly generated object might relate
to the problem at hand.
– “I wish I could…” or “I wonder what would happen • Set quantitative goals
if…” – Set targets, e.g. to generate 10 to 20 concepts.
• Use related stimuli • Use the gallery method
– Good to merge individual and group efforts.
– e.g. generate a list of ideas (working alone) and
– Display a large number of concepts simultaneously for
then pass the list to his or her neighbor. discussion.
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Step 4) Explore Systematically
• After the external and internal search
activities, the team will collect hundreds of
concept fragments – solutions to the sub-
problems.
• E.g. if you have 3 sub-problems and each has
15 fragments, combinations = 15x15x15 =
3,375!
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Concept classification tree Concept Combination Table
1. Pruning of less promising
branches.
2. Identification of independent
approaches to the problem.
3. Exposure of inappropriate
emphasis on certain branches.
4. Refinement of the problem
decomposition for a particular
branch
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Step 5) Reflect on the Solutions and
the process
• Is the team developing confidence that the
solution space has been fully explored?
• Are there alternative function diagrams?
• Are there alternative ways to decompose the
problem?
• Have external sources been thoroughly
pursued?
• Have ideas from everyone been accepted and
integrated in the process?
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